The High TimesCannabis Cup is the world’s foremost cannabis festival. Founded in 1988 by Steven Hager, the High Times Cannabis Cup is held each November in Amsterdam. The event allows judges from around the world to sample and vote for their favorite marijuana varieties. These judges-at-large decide the Cannabis Cup (overall winner in the cannabis variety competition), best new product, best booth, best glass, best hash and best Nederhash. A team of VIP judges decides which seed company has grown the best indica, sativa and hybrid strain and which company has produced the best Neder Hash and best imported hash. The High Times Cannabis Cup also includes live music, educational seminars and an expo for marijuana-related products from cannabis-oriented businesses.

In 2010, High Times mounted its first Cannabis Cup in the United States. The magazine now holds Cannabis Cups in Northern and Southern California, Denver, Michigan, Seattle, with plans to hold a Cannabis Cup in Portland in 2015. The High Times Medical Cannabis Cup celebrates medical marijuana in states that have passed medical marijuana laws. The U.S. Cannabis Cup celebrates marijuana in states that have passed laws that legalize marijuana for adult, recreational use. Like the High Times Cannabis Cup in Amsterdam, marijuana strains are judged and Cups (trophies) are awarded in a number of categories. Teams of expert judges vote on best indica, best sativa, best hybrid, best concentrates, best edibles and highest level of CBD in cannabis products. Attendees vote for best booth, best product sand best glass of each Cannabis Cup expo.

A DVD called High Times Presents: The Cannabis Cup was made after 2003's festival. A film of the 2007 High Times Cannabis Cup, which marked the event's 20th anniversary, was released in the summer of 2008. The 20th High Times Cannabis Cup featured hosts Tommy Chong and Redman.